Laser radar systems have been developed that use retroreflectors such as corner cubes to provide focus adjustment. See, for example, Goodwin et al., U.S. Patent Application Publication 2013/0099957, which is incorporated herein by reference. In some such systems, an interrogation beam makes two passes in a corner cube before being directed to a target. A return beam from the target also makes two passes through the corner cube prior to being directed to a detection system. As a result, the measurement beam associated with a target location experiences twelve reflections at corner cube surfaces. Although losses at these surfaces can be relatively low, even a 4% loss per surface effectively reduces available optical power by about 60%, limiting laser radar performance. Apparatus and methods that exhibit reduced optical losses are needed.